Simplexa Congenital CMV Direct PCR Achieves Near-Perfect Agreement for Newborn Screening in Saliva and Urine
A multicenter study evaluated the Simplexa Congenital CMV Direct real-time PCR assay on over 2,000 newborn saliva and nearly 1,800 urine specimens. The assay demonstrated 98.6% positive and 99.9% negative percent agreement for saliva, and 97.8% and 99.9% for urine, with near-perfect concordance (kappa 0.98). With limits of detection around 300 copies/mL, this extraction-free assay offers a rapid and reliable molecular approach for congenital CMV screening within the critical 21-day diagnostic window.
The original study
Multicenter Evaluation of the DiaSorin Molecular Simplexa Congenital CMV Direct PCR Test on Neonatal Saliva and Urine Specimens.
- Authors
- Dunn JJ, Selvarangan R, Maggert K, Young S, Leber AL
- Journal
- Journal of clinical microbiology
- Type
- Multicenter Study, Journal Article
- PMID
- 37184403
Original abstract
Cytomegalovirus (CMV) is the most common virus associated with congenital infection worldwide and is a major cause of sensorineural hearing loss (SNHL) and developmental delay. Up to 90% of infants with congenital CMV (cCMV) infection are asymptomatic at birth, making the diagnosis challenging. Postnatal diagnosis involves testing newborn saliva and/or urine collected before 21 days of life to confirm cCMV infection. This multicenter study evaluated the performance of the Simplexa Congenital CMV Direct real-time PCR assay for the qualitative detection of CMV in newborn saliva (n = 2,023) and urine (n = 1,797) specimens. Compared to two PCR/bidirectional sequencing assays, the Simplexa Congenital CMV Direct assay demonstrated positive percent agreement (PPA) and negative percent agreement (NPA) of 98.6% and 99.9%, respectively, for saliva samples and a PPA of 97.8% and an NPA of 99.9% for urine specimens. Overall concordance was κ = 0.98 or near perfect compared to the composite reference methods with both sample types. By 95% probit analysis, the limit of detection (LoD) using the AD-169 reference strain was 350 ± 12 copies/mL in urine. The LoDs of saliva swabs in either 1 mL or 3 mL of transport medium were 274 ± 12 copies/mL and 300 ± 14 copies/mL, respectively. The Simplexa Congenital CMV Direct assay can be applied to both saliva and urine specimens collected from newborns less than 21 days of age to rapidly and reliably identify CMV infection.